Chocolate-Peanut Butter Cake

INGREDIENTS

• 1/4 cup reduced-fat creamy peanut butter
• 1/3 cup nonfat cream cheese, softened
• 3 tablespoons margarine, softened
• 1 1/2 cups sugar
• 1/2 cup frozen egg substitute, thawed
• 2 cups sifted cake flour
• 1/4 cup plus 2 tablespoons unsweetened cocoa
• 1 teaspoon baking soda
• 1/4 teaspoon salt
• 1 cup nonfat buttermilk
• 1 teaspoon vanilla extract
• Vegetable cooking spray
• Chocolate Frosting
• 2 tablespoons finely chopped unsalted peanuts